Method of packing fiber for artificial hair

ABSTRACT

[Problems] To provide a method of packing fiber for artificial hair, while suppressing generation of folding mark during packaging, transportation and storage and yet preserving preferable processability and hairdressing characteristics. 
     [Means for Solving Problems] There is provided a method of packing fiber for artificial hair, characterized by packing the artificial hair fibers in a packaging container at a filling density of no lesser than 0.1 kg/l and no more than 0.8 kg/l. Further in the packing method, the pressure of the packed artificial hair fibers applied to the top face of the packaging container is adjusted to no lesser than 0.1 kPa and no more than 8.0 kPa.

TECHNICAL FIELD

The present invention relates to a method of packing fiber for artificial hair, a package thus prepared, and others.

BACKGROUND ART

Various modifications of artificial hair fiber for example in cross section, fineness, raw materials, and others have been studied, for providing artificial hair products, such as wigs, hairpieces, braids, extensions and weavings, with human natural hair-like texture and excellent beauty characteristics.

For example, Patent Literature 1 discloses an irregular-cross section fiber in a shape having a cross section of two or more circles or ellipses partially superimposed or in contact with each other, and having at least one protuberance and/or dent on the peripheral of the circles or ellipses, for the purpose of providing a favorably less glossy and favorably bulky human hair-like fiber.

Alternatively Patent Literature 2 discloses artificial hair fibers of a mixture of an acrylic fiber of a particular composition having a monofilament fineness of 30 to 85 dtex and a vinyl chloride-based fiber having a monofilament fineness of 30 to 85 dtex, for the purpose of providing artificial hair fibers applicable to a variety of styles when used as artificial hairs.

Patent Literature 3 discloses artificial hair fibers bundle of a mixture of hollow and non-hollow fibers of a vinyl chloride resin, for the purpose of providing artificial hair fibers bundle well-balanced in bulkiness and softness.

Patent Literature 1: JPH10-168647A

Patent Literature 2: JP2002-227020A

Patent Literature 3: JP2007-9336A

SUMMARY OF INVENTION Technical Problem

Artificial hair fibers have generally been packaged, as they are packed in a box as fiber bundles (tows). However, the present inventors recently recognized that the fiber bundles packed by such a packing method occasionally have folding mark after transportation and storage of the artificial hair fibers, and that such fiber folding can cause significant problems in processability of the artificial hair fibers and also in beauty characteristic of the artificial hair products obtained.

Accordingly, the inventors have conducted an intensive study to prevent such folding mark. The inventors have found in the study that it was difficult to prevent the folding mark completely only by modification of the cross section, fineness and raw materials of the fiber as described above, and started a study to solve the problems above by developing a new method of packing the artificial hair fibers.

The main object of the present invention, which was made on the basis of the studies, is to provide a method of packing fiber for artificial hair, while suppressing generation of folding mark during packaging, transportation, and storage and yet preserving favorable processability and beauty characteristics.

Solution to Problem

The present invention, which was made to solve the problems above, provides a method of packing artificial hair fibers, characterized by packing artificial hair fibers in a packaging container at a filling density of no lesser than 0.1 kg/l and no more than 0.8 kg/l.

In the packing method, the pressure of the packed artificial hair fibers applied to the top face of the packaging container is preferably no lesser than 0.1 kPa and no more than 8.0 kPa.

In addition, the container used during packing has a value obtained by dividing the area of the bottom face (S) by the height (H) (“S/H”) at no lesser than 30 and no more than 300.

The present invention also provides artificial hair fibers obtained by the packing method, a hair accessory prepared by using the same, and a package of the artificial hair fibers.

In the present invention, the pressure of the packed artificial hair fibers applied to the top face of the packaging container is determined in the following manner:

(1) The volume (V), the area of the top face (T) and the empty weight (a) of the packaging container are determined. (2) The container main body is sealed with a cover while particular sites of the cover are held during measurement of the weight of the empty container, and the maximum weight (b) in the period until the cover is shut completely is determined. (3) The pressure (c) needed for sealing the empty container is determined by a formula “b-a”. (4) The container weight (d) after packing is then determined from the sum of the product of the filling density (D) of the artificial hair fibers in the container and the volume (V) thereof, and the empty weight (a) above (“D×V+a”). (5) The container main body is sealed while a particular site of the cover is held during measurement of the weight of the container after packing, and the maximum weight (e) in the period until the cover is shut completely is determined. (6) The pressure (f) needed to seal the container after packing with the cover is calculated by a formula “e−d−c”. (7) The pressure (g) of the packed artificial hair fibers applied to the top face of the packaging container is determined by dividing the pressure (f) by the area of the top face (T) (“f/T”).

When the container is a container in the configuration in which one side of the cover is connected to the container main body and the container is sealed as the cover is folded at the boundary of the cover with the container main body, such as corrugated fiberboard box, the “particular sites of the cover” means the site at a center of the top face of the folded cover. Alternatively when the container is a container that is closed, as a cover is fitted to the container main body, it may be any site on the cover but, in this case, it should be a site that permits uniform pressurization of the entire face of the cover.

The “hair accessories” in the present invention include artificial hair products such as wigs, hairpieces, braids, extensions, weavings and others, as well as artificial hairs for use as the hairs of dolls.

ADVANTAGEOUS EFFECTS OF INVENTION

It is possible, by the method of packing the artificial hair fibers according to the present invention, to pack artificial hair fibers, while suppressing generation of folding mark during packaging, transportation, and storage and yet preserving favorable processability and beauty characteristics.

DESCRIPTION OF EMBODIMENTS

artificial hair fibers is packed in a packaging container at a filling density of no lesser than 0.1 kg/l and no more than 0.8 kg/l in a method of packing fiber for artificial hair according to the present invention.

Folding mark mostly occurs in the area of the packaging container where the artificial hair fibers bundles are laid one on another or in the corners of the container where the fiber bundles are folded. If artificial hair fibers is packed excessively densely in a packaging container, the fiber bundles in the area where the fiber bundles are overlaid or packed in the corners of the container are folded under large load applied thereon, causing folding mark. In addition, the fiber bundles are more confined and fixed spatially in the packaging container and the same parts of the fiber bundles are consistently laid one on another or placed in the corners of the container, resulting in easier generation of folding mark.

On the contrary, excessively loose packing of artificial hair fibers in a packaging container leads to deterioration in efficiencies of transportation and storage. In addition, the packaging container may become unstabilized and reduced in strength, and may further broken, when piled.

For that reason, the filling density of the artificial hair fibers in the packaging container is preferably 0.1 to 0.8 kg/l and desirably 0.3 to 0.6 kg/l. It is possible by adjusting the filling density in the range above to reduce generation of folding mark, while preserving the transportation and storage efficiencies.

The artificial hair fibers can be packed in a packaging container by heretofore known methods. Generally employed is a method of combining monofilaments obtained after melt spinning, drawing, heat relaxation and other steps into a fiber bundle of a certain total fineness, and dropping the fiber bundles from a chute into a container as they are sprinkled (so-called “sprinkled-into” method). The fiber bundles may be sprinkled into an internal bag that is previously placed in the container.

Generally, fiber bundles are sprinkled-into, while both the chute and the container are rotated for uniform packing of the bundles. Specifically, for example, the chute is so rotated that the fiber bundles drop on the region along a small circle centered at a site slightly displaced from a center of the container. In addition, the container is so rotated that the drop position of the fiber bundles moves along a large circle around the center identical with that of the container. In this way, the fiber bundles are laid uniformly in the container. Such a method can be used preferably in the present invention.

The amount (m) of the sprinkled-into fiber bundles discharged per unit time (hereinafter, referred to as discharge rate, too) is controlled during the sprinkled-into operation, by adjusting the total fineness of the fiber bundles and the feed rate into the chute.

The total fineness of the fiber bundles is determined from the monofilament fineness after the heat-relaxation treatment step described below and the number of monofilaments bundled. Supply of the fiber bundle into chute is synchronized with the heat-relaxation treatment step, and thus, the feed rate of the fiber bundle into chute is determined by the temperature of the heat-relaxation treatment (amount of heat). Specifically, increase of treatment temperature allows faster heat-relaxation thereby to increase the feed rate of the fiber bundle into chute.

The sprinkled-into is continued until the filling density of the fiber bundles becomes in the range described above. When the sprinkled-into period then is designated as t, the product of the discharge rate (m) and the sprinkled-into period (t) (packaging weight: “m×t”) is identical with the product of the volume of the packaging container (V) and the filling density (D) (“V×D”).

After completion of packing, the rotation of the chute and the container is terminated and the fiber bundle is cut. Some of the artificial hair fibers packed then may be exposed from the openings of the container because of its bulkiness. In such a case, it is needed to push the artificial hair fibers into the container with a cover. In the method of packing fiber for artificial hair according to the present invention, the pressure of the artificial hair fibers applied to the top face of the packaging container then is controlled to be no lesser than 0.1 kPa and no more than 8.0 kPa.

If the pressure of the artificial hair fibers applied to the top face of the packaging container is excessively high (in other words, the pressure of the container top face applied to the artificial hair fibers is excessively high), large load is applied to the fiber bundles in the area where the fiber bundles are overlaid and in the corners of the container, leading to generation of folding mark. In addition, the fiber bundles are more confined and fixed spatially in the packaging container and the same parts of the fiber bundles are consistently laid one on another or placed in the corners of the container, resulting in easier generation of folding mark.

On the other hand, if the pressure of the packaging container internal wall applied to the artificial hair fibers is excessively low, the fiber bundles may be disintegrated, and the disintegrated fiber bundles may be entangled in the container during transportation. It is needed to withdraw the fiber bundle from the packaging container during processing of artificial hair products, but, if the fiber bundles are entangled then, the fiber bundles are withdrawn less easily, resulting in significant decrease in processing efficiency.

Thus, the pressure of the artificial hair fibers applied to the top face of the packaging container when the cover of the packaging container is closed is adequately 0.1 to 8.0 kPa, and desirably 1.0 to 6.0 kPa. It is possible to prevent generation of folding mark and to assure preferable supply of the fiber bundle, when the pressure is in the range above.

A packaging machine commonly used can be used in the packaging step, and the processing may be carried out by manual operation. The pressure of the packed artificial hair fibers applied to the top face of the packaging container can be determined in the manner described below. The measurement may be performed every time after packaging, but it is not needed to determine the pressure every time after packaging, if the packaging weight (“m×t”) that can give a pressure to packaging containers used in the range above is determined previously according to the following method.

Specifically in measurement of the pressure of the packed artificial hair fibers applied to the top face of the packaging container, the area of the top face (T) and the empty weight (a) of a packaging container used, and the pressure (c) needed for closing the empty container with the cover are determined previously.

Then in the packing step, the weight of a packaging container (weight (d)=“m×t+a”) containing artificial hair fibers having a particular packaging weight (“m×t” above) is measured, the container main body is closed with the cover while a particular site of the cover is held, and the maximum weight (e) in the period until the cover is shut completely is measured.

The pressure (g) of the packed artificial hair fibers applied to the top face of the packaging container can be determined by dividing the pressure (f) to the cover needed for closing the container after packing, which is obtained by a formula “e−d−c”, by the area of the top face (T) (“f/T”).

If the fiber bundle is packed by a packaging machine, the packaging operation may be carried out, as the pressure (g) is monitored by using an instrument equipped with weight-measuring means and pressure (g)-calculating means. The weight-measuring means for use may be a weight scale commonly used that determines the weight of the packaging container, as the packaging container is placed thereon. The calculation means for use may be a general-purpose computer and program. The packaging machine desirably has an additional function to stop operation and set off alarm when the pressure (g) rises or declines beyond the range of 0.1 kPa to 8.0 kPa described above.

The packaging container for use in the method of packing fiber for artificial hair according to the present invention has a value, which is obtained by dividing the area of the bottom face (S) (cm²) by the height (H) (cm) of the container (“S/H”) (cm), of no lesser than 30 and no more than 300.

When the S/H value is larger than 300 (i.e., the bottom face area is greater, compared to the height), a fiber bundle is in contact with another fiber bundle more frequently during withdrawal of the fiber bundles from the packaging container, leading to more entanglement of the fiber bundles.

On the other hand, when the S/H value is less than 30, since the container height is greater compared to the bottom face area, the containers are less stable and may be broken as the strength is not sufficiently high, when the packaging containers are piled.

Accordingly, the S/H value of the packaging container is preferably 30 to 300, and desirably 50 to 250. It is possible to assure preferable withdrawal of the fiber bundles and stabilized piling of the packaging containers, when the value is in the range above.

The packaging container commonly used is a corrugated fiberboard box, but may be a container made of a plastic or the like, and the material is not particularly limited. The size and the shape of the packaging container are not particularly limited either.

Generally, the packed artificial hair fibers is withdrawn during processing and cut to a desired particular length (ten to dozens of centimeters), blended with a hair with desired color and length (hackling), and then, machine-processed into woven-hair, and further converted to a product after curling/setting, sewing, and finishing steps. Artificial hair fibers often had folding mark when processed by conventional packing methods, and thus, the conventional methods have a problem that the operational efficiency is lowered significantly by the labor for its correction. In addition, Woven-hair and the hair accessories (products) obtained were unsatisfactory in linearity and also uniformity in thickness of the hair, causing problems in beauty characteristics.

In contrast, it is possible by the method of packing the artificial hair fibers according to the present invention to obtain artificial hair fibers without folding mark, and thus to assure high operational efficiency. In addition, Woven-hair and other products obtained are preferable in linearity and uniformity in thickness of the hair, assuring superior beauty characteristics.

The average fineness of the artificial hair fibers for use in the present invention is preferably 30 to 100 dtex, more preferably 40 to 90 dtex and still more preferably 50 to 80 dtex. Use of artificial hair fibers having an average fineness of less than 30 dtex may lead to deterioration in combing efficiency. On the other hand, use of artificial hair fibers having an average fineness of more than 100 dtex, which is higher in rigidity, leads to deterioration in appearance. The average fineness was determined by selecting 100 monofilaments at random from a fiber bundle, measuring the weight of 1 meter of the monofilaments “M”, and converting it to the weight per 10,000 m, and by calculation according to the following formula: “M×10⁴/100”.

Various synthetic fibers are usable as the artificial hair fibers. In particular, fibers based on vinyl chloride, acrylic, polyester, polypropylene, nylon, and polylactic acid are used practically, and in particular, vinyl chloride-based and acrylic fibers are preferable. More preferably, vinyl chloride-based fibers are preferable, from a viewpoint of the properties of strength, glossiness, hue, flame resistance, texture, heat shrinkage, and others. Hereinafter, specific examples of the vinyl chloride-based fibers will be described.

Vinyl chloride resins prepared by bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization and others can be used for vinyl chloride-based fibers, but those prepared by suspension polymerization are preferably used, for example from the point of early-stage color-developing efficiency of the monofilament.

The vinyl chloride resin is not particularly limited, if it is a homopolymer resin, i.e., a homopolymerization product, of a heretofore known vinyl chloride or one of heretofore known various copolymer resins. Any heretofore known copolymer resin may be used as the copolymer resin. Typical examples thereof include vinyl chloride-vinyl ester copolymer resins such as vinyl chloride-vinyl acetate copolymer resins, and vinyl chloride-vinyl propionate copolymer resins; vinyl chloride-acrylic ester copolymer resins such as vinyl chloride-butyl acrylate copolymer resins, and vinyl chloride-2-ethylhexyl acrylate copolymer resins; vinyl chloride-olefin copolymer resins such as vinyl chloride-ethylene copolymer resins, and vinyl chloride-propylene copolymer resins; vinyl chloride-acrylonitrile copolymer resins; and the like. Particularly preferably, homopolymer resins (homopolymerization products) of vinyl chloride, vinyl chloride-ethylene copolymer resins, vinyl chloride-vinyl acetate copolymer resins, and the like are used. The content of the comonomer in the copolymer resins above can be determined arbitrarily according to required qualities such as molding processability and fiber properties. The comonomer content is preferably 2 to 30% by weight, and particularly preferably 2 to 20% by weight.

The viscosity-average polymerization degree of the vinyl chloride resin is preferably 600 to 2500, and more preferably 600 to 1800. A vinyl chloride resin having a viscosity-average polymerization degree of less than 600 may have a lower melt viscosity and give a monofilament easily shrinkable by heat. On the other hand, a vinyl chloride resin having a viscosity-average polymerization degree of more than 2500 may have a higher melt viscosity, leading to increase of nozzle pressure and making it difficult to give the product safely. The viscosity-average polymerization degree was determined by dissolving 200 mg of a resin in 50 ml of nitrobenzene, measuring the specific viscosity of the polymer solution in a thermostatic oven at 30° C. by using a Ubbelohde viscometer, and calculating it according to JIS K6720-2.

Heretofore known heat stabilizers can be used as the heat stabilizers. In particular, one or more kinds of heat stabilizers selected from Ca—Zn-based heat stabilizers, hydrotalcite-based heat stabilizers, tin-based heat stabilizers, and zeolite-based heat stabilizers are used preferably. The heat stabilizer is used for improvement in resistance to thermal decomposition, long-term stability during molding, and hue of the resulting filament. In particular, combined use of a Ca—Zn-based heat stabilizer and a hydrotalcite-based heat stabilizer is preferable, as it gives a preferable balance between molding processability and filament properties. These heat stabilizers are used in an amount of preferably 0.1 to 5.0 parts by weight, and more preferably 0.3 to 3.0 parts by weight, with respect to 100 parts by weight of the vinyl chloride resin. The hydrotalcite-based heat stabilizer is specifically a hydrotalcite compound, and more specifically, it is a composite salt compound containing magnesium and/or alkali metal, aluminum or zinc, magnesium and aluminum, of which the crystal water was dehydrated. The hydrotalcite compound may be a natural or synthetic product, and the synthetic product may be prepared by any heretofore known methods.

The resin composition for forming the fiber bundle according to the present invention contains, according to application, heretofore known additives used in vinyl chloride resin, in addition to the vinyl chloride resin. Examples thereof include lubricants, compatibilizing agents, processing aids, reinforcing agents, ultraviolet absorbents, antioxidants, antistatic agents, fillers, flame retardants, pigments, early-stage coloring improvers, conductivity-enhancing agents, surface-finishing agents, photostabilizers, flavoring agents, and the like.

Hereinafter, the method of producing artificial hair fibers bundle according to the present invention will be described briefly. The resin composition used may be a powder compound prepared in a heretofore known mixer, such as Henschel Mixer, super mixer or ribbon blender, or a pelletized compound prepared by melt-mixing of the powder compounds. The powder compound can be produced under a heretofore known common condition, and may be produced under a hot or cold blend, but in particular, a hot blend in which the cut temperature during blending is raised to 105 to 155° C., is preferable for reduction of volatile materials in the resin composition. The pelletized compound is produced in a manner similar to production of common vinyl chloride-based pelletized compounds. For example, such a pelletized compound can be prepared by using a kneading machine such as single screw extruder, double screw extruder with the screws rotating in different directions, conical double screw extruder, double screw extruder with the screws rotating in the same direction, co-kneader, planetary gear extruder or roll kneading machine. The condition for production of the pelletized compound is not particularly limited, but the resin temperature is preferably set to be 185° C. or lower.

Conversion from resin composition to fibrous undrawn filament is carried out by a heretofore known spinning method. The spinning method is not particularly limited, but is preferably a melt spinning method. Heretofore known extruders can be used for the melt spinning. For example, a single screw extruder, a double screw extruder with the screws rotating in different directions, a conical double screw extruder, or the like may be used, but in particular, a single screw extruder having a screw diameter of about 35 to 85 mmφ, or a conical extruder having a screw diameter of about 35 to 50 mmφ is preferably used. Excessively large screw diameter leads to increase in extrusion amount and excessive increase in nozzle pressure, which in turn may lead to excessively fast flow of the undrawn filaments, making it difficult to wind the filaments.

Heretofore known nozzles may be used in melt spinning. A nozzle in a shape similar to the cross section of the desired monofilament is connected to the end part of the die (spinning die) for melt spinning. Considering the properties for hair dressing such as curling property, the vinyl chloride resin composition is preferably processed, as it is melted and extruded, through a multi-type nozzle plate having multiple nozzle holes having a nozzle-hole sectional area of 0.5 mm² or less, as it is connected to the die (nozzle hole number: 50 to 300, and nozzle array number: 1 to 5) into strands of undrawn filaments having a monofilament fineness of 300 dtex or less.

Specifically, undrawn filaments are obtained, for example, by melt-spinning of a pelletized compound of a resin composition at a die temperature of 160 to 190° C., and more preferably 165 to 185° C., by using a single screw extruder. When the fineness of the undrawn filament is more than 300 dtex, it is needed to increase the draw rate during drawing treatment to obtain low-fineness monofilaments, and the low-fineness monofilament after the drawing treatment have glossy appearance, thereby making it difficult to bring the monofilaments in the semi- to 70%-glossiness state. In addition, the spinning is preferably carried out at a nozzle pressure of 50 MPa or less during melt spinning. A nozzle pressure of more than 50 MPa leads to excessive increase of the load applied to the thrust region of the extruder, easily causing troubles of the extruder and possibly leading also to “resin leakage” from the connected regions such as of turn head and die.

The undrawn filaments obtained by melt spinning is subjected to drawing and heat treatment by a known method to give monofilaments (drawn filaments) having a low fineness of 100 dtex or less. As for the drawing condition, the draw rate is preferably about 200 to 400% at a drawing temperature of 90 to 120° C. in air. A drawing temperature of lower than 90° C. gives a monofilament lower in strength, and also causes filament breakage easily, while a drawing temperature of higher than 120° C. may lead to deterioration in touch feeling of the monofilament, i.e., conversion to plastic-like touch feeling. Moreover, a draw rate of less than 200% leads to insufficient expression of the strength of the monofilament, while a draw rate of more than 400% may lead to increase in frequency of filament breakage during drawing.

In addition, the heat shrinkage percentage of the monofilament can be reduced by subjecting the monofilament to a heat-relaxation treatment of treating the filaments in air kept at a temperature of 110 to 140° C. for relaxation to a length of 60 to 95% of the length before heat relaxation treatment. The heat relaxation treatment can be carried out simultaneously or separately with the drawing treatment. Various heretofore known melt spinning technologies, such as those concerning nozzle cross section, heated tube, drawing treatment, and heat treatment, can also be used arbitrarily in combination in the present invention.

The method of producing artificial hair fibers has been described above, by taking vinyl chloride-based fibers as examples. Various synthetic fibers can be used as the artificial hair fibers, as described above, and the heat stabilizer and additives added, the conditions of the spinning method and the drawing/heat relaxation processing and other treatments are used, as selected most suitably according to the synthetic fiber used. For example, when a fiber of a vinyl chloride-acrylonitrile copolymer resin is used, the spinning method used is a solution spinning method of preparing a spinning dope by dissolving the copolymer resin in acetone and extruding the spinning dope through spinning nozzles into an aqueous acetone solution.

The method of packing fiber for artificial hair according to the present invention is applicable widely to artificial hair fibers of various synthetic fibers.

EXAMPLES Example 1 (A) Production of Artificial Hair Fiber

A mixture containing 100 parts by weight of a vinyl chloride resin (TH-1000, manufactured by Taiyo Vinyl Corp., viscosity-average polymerization degree: 1000), 3 parts by weight of a hydrotalcite-based composite stabilizer (CP-410A, manufactured by Nissan Chemical Industries), 0.5 part by weight of an epoxidized soy bean oil (O-130P, manufactured by Asahi Denka), and 0.8 part by weight of an ester-based lubricant (EW-100, manufactured by Riken Vitamin) was heated to 100° C. under agitation in a Henschel mixer, to give a resin composition.

The resin composition obtained was melt-spun through a spinning die having a nozzle cross section in the high-density cross-sectional shape (see FIG. 1(A)) (nozzle cross-sectional area: 0.06 mm², hole number: 120) in a 40-mm single-screw extruder controlled between 175 to 185° C. at a die temperature of 180° C. and an extrusion quantity of 10 kg/h, to give undrawn filaments having an average fineness of 160 dtex.

Subsequently, the melt-spun fiber was drawn to 300% in air at 100° C. and was subjected to heat-relaxation treatment in air at 140° C. for shrinkage to a total fiber length of 75% of that before treatment, to give artificial hair fibers having an average fineness of 65 dtex.

(B) Filling and Packing into Container

The artificial hair fibers above were combined to a fiber bundle having a total fineness of 1,707,000 dtex, which was packed into a corrugated fiberboard box (45 cm in length, 45 cm in width and 20 cm in height, bottom face area (S)/height (H)=101) by the sprinkled-into method.

A chute vertical in the upper region into which the fiber bundle is supplied and bent in the “<” shape in the lower region from which the fiber bundle is discharged was used as the chute. The chute was rotated around the rotating axis located at the center of the corrugated fiberboard bottom face at a frequency of 40 rpm. The “<”-shaped discharge port for discharging the fiber bundle in the lower region of the chute moves then along the circumference of a circle separated by 15 cm from the center of the corrugated fiberboard box bottom face.

In addition, the corrugated fiberboard was rotated by using the center of the bottom face as axis, while the rotational frequency was changed in the range of 10 to 30 rpm.

The fiber bundle was packed uniformly into the corrugated board box, as the diameter of the circle drawn by the fiber bundle sprinkled into the corrugated board box was altered by rotating the chute and the corrugated board box simultaneously in this way.

The discharge rate was 3 kg/min, and the fiber bundle was packed to a filling density of 0.5 kg/l.

The pressure of the packed artificial hair fibers applied to the top face of the container while the corrugated fiberboard box after packing is closed was determined in the following manner:

(1) The empty weight (a) of an empty corrugated board box is determined. In the present Example, the weight (a) was 1.4 kg.

(2) The weight (b) of the corrugated fiberboard box when the top face covers of the corrugated fiberboard box are sequentially folded manually and the top face covers are closed, as the top face was pressed manually, during measurement of the weight of the empty corrugated board box as it is placed on a weight scale was determined. The weight (b) was 2.4 kg.

(3) The pressure (c) to the top-face cover needed to seal the empty corrugated fiberboard box is calculated by a formula “b-a”. The pressure (c) was 1.0 kg.

(4) The fiber bundle is then packed in the corrugated fiberboard box at a filling density of (0.5 kg/1), and the weight (d) thereof is determined. The weight (d) was 20.25 kg.

(5) While the weight of the corrugated board after packing is determined as it is placed on a weight scale, the top-face covers were closed by folding the top face covers of the corrugated board box sequentially and pressing the center of the top face manually, together with the fiber bundle extending out of the corrugated fiberboard box. The weight (e) then was 78.45 kg.

(6) The pressure (f) needed to close the corrugated fiberboard box after packing with the cover is calculated by “e−d−c”. The pressure (f) was 57.2 kg.

(7) The pressure (g) of the packed artificial hair fibers applied to the top face of the corrugated fiberboard box is calculated, by dividing the pressure (f) by the area of the top face (T=45 cm×45 cm). The pressure (g) was 2.7 kPa.

(C) Evaluation (1) Folding Mark

A package was left under an environment at a temperature of 60° C. and a relative humidity of 50% for 72 hours, and then, 10 monofilaments of 30 cm in length were collected from the fiber bundle. The average of the values of “linear length (L) (cm) of deformed monofilament between edges/real length of monofilament (L₀) (cm)” of the collected monofilaments was determined, and the folding mark was evaluated according to the following evaluation criteria:

“Good”: L/L₀ is 85 or more (no folding mark observed)

“Fair”: L/L₀ is 75 or more and less than 85 (slight folding mark observed)

“Bad”: L/L₀ is less than 75 (distinctive folding mark observed)

(2) Withdrawal Efficiency

A package was sprinkled into a shaker (Yamato Shaker MODEL SA-31) under a constant-velocity condition (207 reciprocations/minute) for 6 hours, and one end of the fiber bundle was held and withdrawn gradually out of the container. The withdrawal efficiency then was evaluated according to the following criteria:

“1”: Fiber bundle mostly disintegrated and entangled, completely prohibiting withdrawal of the fiber bundle

“2”: Fiber bundle disintegrated and entangled, making withdrawal of the fiber bundle difficult

“3”: Fiber bundle only slightly disintegrated and entangled, allowing discharge of the fiber bundle without difficulty

“4”: Fiber bundle only slightly disintegrated and entangled, allowing withdrawal at preferable withdrawal efficiency

“5”: Fiber bundle without disintegration or entanglement, allowing withdrawal at preferable withdrawal efficiency

(3) Resistance to Withdrawal

A package was sprinkled into a shaker (Yamato Shaker MODEL SA-31) under a constant-velocity condition (207 reciprocations/minute) for 6 hours, and then, the fiber bundle was withdrawn by hands, while one point of the fiber bundle is fixed to a position 50 cm above the center of the container bottom face. The resistance to withdrawal then was evaluated according to the following criteria:

“1”: No fiber bundle withdrawn, prohibiting evaluation itself

“2”: Withdrawn fiber bundle containing many disintegrated regions in the later stage of withdrawal, because of simultaneous withdrawal with other fiber bundles, causing disintegration in other fiber bundles

“3”: Withdrawn fiber bundle apparently causing simultaneous withdrawal with other fiber bundles, but the bundles being separated completely during withdrawal, causing no trouble in operation

“4”: Withdrawn fiber bundle causing simultaneous withdrawal with other fiber bundles only slightly, allowing preferable withdrawal operation

“5”: Withdrawn fiber bundle causing no simultaneous withdrawal with other fiber bundle, allowing preferable withdrawal efficiency

Evaluation results are summarized in “Table 1”.

TABLE 1 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 Packing Filling Density (kg/l) 0.50 0.30 0.40 0.60 0.10 0.20 0.70 0.80 condition Pressure applied to 2.7 0.2 0.8 5.3 0 0 7.8 10.5 packaging container top face (kPa) Area of the bottom 101 101 101 101 101 101 101 101 face of container (S)/height (H) Evaluation Folding mark 94 96 96 90 97 97 85 79 results Withdrawal 5 4 4 5 3 3 58 5 efficiency Resistance to 5 4 4 5 3 3 5 5 withdrawal Ex. 9 Ex. 10 Ex. 11 Ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16 Packing Filling Density (kg/l) 0.50 0.50 0.50 0.50 0.80 0.80 0.80 0.80 condition Pressure applied to 2.6 2.4 2.3 2.0 10.3 10.0 9.8 9.5 packaging container top face (kPa) Area of the bottom 216 300 360 490 216 300 360 490 face of container (S)/height (H) Evaluation Folding mark 94 94 94 94 79 79 79 79 results Withdrawal 5 5 5 5 5 5 5 5 efficiency Resistance to 5 4 3 3 5 4 3 3 withdrawal

Consequently, the folding mark was found to be “good”, as L/L₀ is 94. In addition, the withdrawal efficiency and the resistance to withdrawal were also preferable and both rated at “5”.

Examples 2 to 8

The filling density was studied in Examples 2 to 8. Packaging was carried out in a manner similar to Example 1, except the filling density.

The filling density was 0.3 kg/l in Example 2. The pressure of the artificial hair fibers applied to the top face of the container then was 0.2 kPa. Similarly, the filling density was 0.4 kg/l (pressure to the top face of the container: 0.8 kPa) in example 3; the filling density was 0.6 kg/l (pressure: 5.3 kPa) in Example 4; the filling density was 0.1 kg/l (pressure: 0 kPa) in Example 5; the filling density was 0.2 kg/l (pressure: 0 kPa) in Example 6; the filling density was 0.7 kg/l (pressure: 7.8 kPa) in Example 7; and the filling density was 0.8 kg/l (pressure: 10.5 kPa) in Example 8.

[0058]

Consequently, the L/L₀ values were 79 or more and the folding mark was rated “fair” in all Examples 2 to 8. The withdrawal efficiency and the resistance to withdrawal were also preferable, and both of them were rated at “3” or higher. In particular in Examples 2 to 4, the L/L₀ values were 90 or more, and the withdrawal efficiency and the resistance to withdrawal were evaluated preferable at a rating of “4” or higher.

Examples 9 to 16

The container shape (bottom face area (S)/height (H)) was studied in Examples 9 to 16. The height of the corrugated board box was altered, while the length and width thereof were left constant, respectively at 45 cm and 45 cm, for change of the S/H value.

In Examples 9 to 12, packaging was carried out in a manner similar to Example 1, except the container shape. The S/H value was 216 in Example 9. The pressure of the artificial hair fibers applied to the top face of the container then was 2.6 kPa. Similarly, the S/H value was 300 (pressure to container top face: 2.4 kPa) in Example 10; the S/H value was 360 (pressure: 2.3 kPa) in Example 11; and the S/H value was 490 (pressure: 2.0 kPa) in Example 12.

Consequently in all Examples 9 to 12, the folding mark was rated “good”, as the L/L₀ value was 94. In addition, the withdrawal efficiency and the resistance to withdrawal were also preferable and rated all at “3” or higher. In particular in Examples 9 and 10, the withdrawal efficiency and the resistance to withdrawal were evaluated preferable at a rating of “4” or higher.

Subsequently in Examples 13 to 16, packaging was carried out in a manner similar to Example 8, except for the container shape. The S/H value was 216 in Example 13. The pressure of the artificial hair fibers applied to the top face of the container then was 10.3 kPa. Similarly, the S/H value was 300 (pressure to container top face: 10 kPa) in Example 14; the S/H value was 360 (pressure: 9.8 kPa) in Example 15; and the S/H value was 490 (pressure: 9.5 kPa) in Example 16.

Consequently in all Examples 13 to 16, the folding mark was evaluated to be “fair”, as the L/L₀ value was 79. In addition, the withdrawal efficiency and the resistance to withdrawal were also evaluated preferably at a rating of “3” or higher.

Comparative Example 1

Cases when the filling density is lower were studied in Comparative Example 1. Packaging was carried out in a similar manner to Example 1, except that filling density was 0.05 kg/L. The pressure of the artificial hair fibers applied to the top face of the container then was 0 kPa.

Consequently, the folding mark was evaluated to be “good”, as the L/L₀ value was 97. However, the withdrawal efficiency and the resistance to withdrawal were both rated at “1,” prohibiting withdrawal of the fiber bundle (see “Table 2”).

TABLE 2 Comparative Comparative Comparative Comparative Comparative Comparative Comparative Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Packing Filling Density (kg/l) 0.50 0.05 0.05 0.05 0.05 0.90 1.00 condition Pressure applied to 0 0 0 0 0 12.4 1.43 packaging container top face (kPa) Area of the bottom face 101 216 300 360 490 101 101 of container (S)/height (H) Evaluation Folding mark 97 97 97 97 97 67 55 results Withdrawal efficiency 1 1 1 1 1 5 4 Resistance to 1 1 1 1 1 5 4 withdrawal

Comparative Examples 2 to 5

The container shapes in cases when the filling density was set to be lower were studied in Comparative Examples 2 to 5. In Comparative Examples 2 to 5, packaging was carried out in a manner similar to Examples 9 to 12, except that the filling density was 0.05 kg/l. In any one of Comparative Examples 2 to 5, the pressure of the artificial hair fibers applied to the top face of the container then was 0 kPa.

Consequently, the folding mark was evaluated to be “good”, as the L/L₀ value was 97. However, the withdrawal efficiency and the resistance to withdrawal were both rated at “1,” prohibiting withdrawal of the fiber bundle.

Comparative Examples 6 and 7

Cases when the filling density was set to be higher were studied in Comparative Examples 6 and 7. Packaging was carried out in a similar manner to Example 1, except that filling density was set to 0.90 or 1.00 kg/l. The pressure of the artificial hair fibers applied to the top face of the container then was 12.4 or 14.3 kPa.

Consequently in Comparative Example 6, the withdrawal efficiency and the resistance to withdrawal were evaluated preferably at a rating of “5”, but the folding mark was evaluated to be “bad”, as the L/L₀ value was 67. Alternatively, the L/L₀ value was 55 in Comparative Example 7, indicating generation of distinguished folding mark.

The results above show that it is possible to prevent folding mark and obtain preferable withdrawal efficiency and resistance to withdrawal by adjusting the filling density of the artificial hair fibers in packaging container in the range of 0.1 to 0.8 kg/1, and more preferably in the range of 0.3 to 0.6 kg/l.

The results also showed that it is possible to prevent folding mark and improve the withdrawal efficiency and the resistance to withdrawal of the fiber bundle, by adjusting the pressure of the packed artificial hair fibers applied to the top face of the packaging container and the container shape (S/H) in suitable ranges.

Examples 17 to 32 and Comparative Examples 8 to 14

Tests were carried out by using artificial hair fibers having different cross-sectional shapes in Examples 17 to 32 and Comparative Examples 8 to 14.

Specifically, artificial hair fibers obtained by melt spinning of a resin composition by using a spinning die having a nozzle cross section in a low-density cross-sectional shape (see FIG. 1(B)) (nozzle cross-sectional area: 0.06 mm², hole number: 120) was used. The average fineness of the artificial hair fibers (undrawn filament) was 160 dtex. Subsequently, the melt-spun fiber was drawn by 300% in air at 100° C. and heat-relaxation treated in air at 140° C. for shrinkage to a total length of 75% of the fiber before treatment, to give artificial hair fibers having an average fineness of 65 dtex.

In Example 17, packaging was carried out in a similar manner to Example 1, by using artificial hair fibers in a low-density cross-sectional shape. In Examples 18 to 32 and Comparative Examples 8 to 14, studies were made similarly to the corresponding Examples 2 to 16 and Comparative Examples 1 to 7, except that the artificial hair fibers was changed to that in a low-density cross-sectional shape.

Evaluation results are summarized in “Table 3” and “Table 4”.

TABLE 3 Ex. 17 Ex. 18 Ex. 19 Ex. 20 Ex. 21 Ex. 22 Ex. 23 Ex. 24 Packing Filling Density (kg/l) 0.50 0.30 0.40 0.60 0.10 0.20 0.70 0.80 condition Pressure applied to 6.5 3.2 4.7 7.9 0 1.0 10.6 11.7 packaging container top face (kPa) Area of the bottom 101 101 101 101 101 101 101 101 face of container (S)/height (H) Evaluation Folding mark 86 91 88 83 95 93 77 75 results Withdrawal 5 5 5 5 3 5 5 5 efficiency Resistance to 5 5 5 5 3 5 5 5 withdrawal Ex. 25 Ex. 26 Ex. 27 Ex. 28 Ex. 29 Ex. 30 Ex. 31 Ex. 32 Packing Filling Density (kg/l) 0.50 0.50 0.50 0.50 0.80 0.80 0.80 0.80 condition Pressure applied to 6.2 6.0 5.8 5.6 11.6 11.5 11.3 11.0 packaging container top face (kPa) Area of the bottom 216 300 360 490 216 300 360 490 face of container (S)/height (H) Evaluation Folding mark 86 86 86 86 75 75 75 75 results Withdrawal 5 5 5 5 5 5 5 5 efficiency Resistance to 5 4 3 3 5 4 3 3 withdrawal

TABLE 4 Comparative Comparative Comparative Comparative Comparative Comparative Comparative Ex. 8 Ex. 9 Ex. 10 Ex. 11 x. 12 Ex. 13 Ex. 14 Packing Filling Density (kg/l) 0.50 0.05 0.05 0.05 0.05 0.90 1.00 condition Pressure applied 0 0 0 0 0 1.46 18.0 to packaging container top face (kPa) Area of the 101 216 300 360 490 101 101 bottom face of container (S)/height (H) Evaluation Folding mark 95 95 95 95 95 51 40 results Withdrawal 1 1 1 1 1 5 4 efficiency Resistance to 1 1 1 1 1 5 3 withdrawal

The results showed that the filling density is preferably 0.1 to 0.8 kg/1, and particularly favorably 0.3 to 0.6 kg/l, even for the artificial hair fibers in the low-density cross-sectional shape. The results also showed that the artificial hair fibers in the low-density cross-sectional shape are superior in resistance to folding mark, withdrawal efficiency and resistance to withdrawal even at a filling density of 0.2 kg/l.

It was also found that it is possible to further prevent generation of the folding mark and improve withdrawal efficiency and resistance to withdrawal by adjusting the pressure of the artificial hair fibers applied to the top face of the container and the container shape S/H in suitable ranges.

Examples 33 to 48 and Comparative Examples 15 to 21

Artificial hair fibers of an acrylic resin were used in the studies in Examples 33 to 48 and Comparative Examples 15 to 21.

The acrylic-resin artificial hair fiber used was a commercially available product (KL-S, manufactured by Kaneka Corporation). The cross-sectional shape was dumbbell-like (similar to the low-density cross-sectional shape shown in FIG. 1(A)), and the average fineness was 55 dtex.

In Example 33, packaging was carried out in a similar manner to Example 1, except the artificial hair fiber of an acrylic resin in a low-density cross-sectional shape was used. Also in Examples 33 to 48 and Comparative Examples 15 to 21, studies were made similarly to the corresponding Examples 2 to 16 and Comparative Examples 1 to 7, except that the artificial hair fiber was changed to that of the acrylic resin in a low-density cross-sectional shape.

Evaluation results are summarized in “Table 5” and “Table 6”.

TABLE 5 Ex. 33 Ex. 34 Ex. 35 Ex. 36 Ex. 37 Ex. 38 Ex. 39 Ex. 40 Packing Filling Density (kg/l) 0.50 0.30 0.40 0.60 0.10 0.20 0.70 0.80 condition Pressure applied to 7.0 3.6 4.8 9.2 0 1.2 10.9 11.8 packaging container (S)/height (H) Area of the bottom 101 101 101 101 101 101 101 101 face of container (S)/height (H) Evaluation Folding mark 83 90 87 80 95 93 77 75 results Withdrawal 5 5 5 5 3 5 5 5 efficiency Resistance to 5 5 5 5 3 5 5 5 withdrawal Ex. 41 Ex. 42 Ex. 43 Ex. 44 Ex. 45 Ex. 46 Ex. 47 Ex. 48 Packing Filling Density (kg/l) 0.50 0.50 0.50 0.50 0.80 0.80 0.80 0.80 condition Pressure applied to 6.9 6.9 6.7 6.6 11.8 11.7 1.6 11.5 packaging container (S)/height (H) Area of the bottom face 216 300 360 490 216 300 360 490 of container (S)/height (H) Evaluation Folding mark 83 84 83 83 75 75 75 75 results Withdrawal 5 5 5 5 5 5 5 3 efficiency Resistance to 5 4 3 3 5 4 3 3 withdrawal

TABLE 6 Comparative Comparative Comparative Comparative Comparative Comparative Comparative Ex. 15 Ex. 16 Ex. 17 Ex. 18 Ex. 19 Ex. 20 Ex. 21 Packing Filling Density (kg/l) 0.50 0.05 0.05 0.05 0.05 0.90 1.00 condition Pressure applied to 0 0 0 0 0 15.0 17.9 packaging container top face (kPa) Area of the bottom face 101 216 300 360 490 101 101 of container (S)/height (H) Evaluation Folding mark 95 95 95 95 95 49 39 results Withdrawal 1 1 1 1 1 5 4 efficiency Resistance to 1 1 1 1 1 5 3 withdrawal

Consequently, it was found that the filling density is preferably 0.1 to 0.8 kg/1, and particularly preferably 0.3 to 0.6 kg/1, also for the artificial hair fibers of acrylic resin in the low-density cross-sectional shape. The artificial hair fibers of acrylic resin gave results preferable in resistance to folding mark, withdrawal efficiency, and resistance to withdrawal, even at a filling density of 0.2 kg/l.

It was also found that it is possible to prevent folding mark and improve withdrawal efficiency, and resistance to withdrawal, by adjusting the pressure of the artificial hair fibers applied to the top face of the container and the container shape S/H in suitable ranges.

INDUSTRIAL APPLICABILITY

The present invention is used in packaging, transportation and storage of artificial hair fibers used in artificial hair products such as wigs, hairpieces, braids, extensions, and weavings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is illustrating a cross-sectional shape of artificial hair fibers used in Examples: (A): fiber in a high-density cross-sectional shape, and (B): fiber in a low-density cross-sectional shape. 

1. A method of packing fiber for artificial hair, characterized by packing artificial hair fibers in a packaging container at a filling density of no less than 0.1 kg/l and no more than 0.8 kg/l.
 2. The method of packing fiber for artificial hair according to claim 1, wherein the pressure of the packed artificial hair fibers applied to the top face of the packaging container is no less than 0.1 kPa and no more than 8.0 kPa.
 3. The method of packing fiber for artificial hair according to claim 1, wherein the value obtained by dividing the area of the bottom face (S) of the packaging container by the height (H) of the packaging container (S/H) is no less than 30 and no more than
 300. 4. An artificial hair fiber, obtained by the method of packing fiber for artificial hair according to claim
 1. 5. A hair accessory, prepared by using the artificial hair fibers obtained by the method of packing fiber for artificial hair according to claim
 1. 6. A package of packed artificial hair fibers, characterized in that the artificial hair fibers is packed in a packaging container at a filling density of no less than 0.1 kg/l and no more than 0.8 kg/l. 